When he opened the door of the cell in the tower, he fully expected to find the two boys there.

Where were they?

By what jugglery had they contrived to get out of such a formidable fortress as that place?

This the present chapter is to relate.

To give it clearly, however briefly, we must go back to the day of their entrance into their gloomy prison home.

Jack and Harry were alone.

"This is a rum go, Jack," said Harry Girdwood. "What do you think of it?"

"Precious dull, old boy," grumbled young Harkaway.

"Better than a grave on the mountain side."

"It is just that," said young Jack. "But it wouldn't be quite so good if this sort of thing was meant to be permanent."